litterbox

How can you not be interested in a project that uses load cells, Bluetooth, a Raspberry Pi, and Twitter. Even for those of our readers without a cat, [Scott’s] tweeting litter box is worth the read.

Each aspect of this project can be re-purposed for almost any application. The inexpensive load cells, which available from eBay and other retailers, is used to sense when a cat is inside the litter box. Typically sensors like the load cell (that contain a strain gauge) this use a Wheatstone bridge, which is very important for maximizing the sensitivity of resistive sensor. The output then goes to a HX711, which is an ADC specifically built for load cells. A simple alternative would be using an instrumentation amplifier and the built-in ADC of the Arduino. Now, the magic happens. The weight reading is transmitted via an HC-06 Bluetooth module to a Raspberry Pi. Using a simple Perl script, the excreted weight, duration, and the cat’s resulting body weight is then tweeted!

Very nice work! This is a well thought out project that we could see being expanded to recognize the difference between multiple cats (or any other animal that goes inside).

[ScottSEA] has six cats. As you can imagine, with six cats, a simple litter box just doesn’t cut it. [ScottSEA] uses the CatGenie. While a self cleaning cat toilet is a technical marvel, it has one major drawback. Much like an ink jet printer, it has disposable cartridges. Those cartridges, just ike some print cartridges, have a built in counter that disables them after so many uses. After adding up the totals for six cats worth of cartridge use, [ScottSEA] started hacking. He has posted directions on how to manually refill them, as well as reset the internal counter using an Arduino.

We suggest that he find a way to harness all that cat power for his home electronics. How many watts could you produce per cat?